Arc-resistant switchgear enclosures house medium voltage electrical switchgear components such as potential transformers (PT), fuses, circuit breakers, etc. A typical enclosure has plural compartments, with each compartment housing one or more electrical components. Medium voltage generally is in the 5-38 KV range.
Such medium voltage electrical components can experience arc faults. An arc fault creates an explosion of hot gasses which can endanger nearby personnel and equipment.
In order to protect nearby personnel and equipment, enclosures are metal clad and are designed to contain the explosion and vent the explosive gasses in a controlled manner. Personnel and equipment at the front, sides and rear of an enclosure are protected by the walls of the enclosure. The explosive gasses are typically vented up into a plenum which channels the explosive gasses to a safe area, such as a building exterior.
Access to each compartment in the enclosure is provided by a door. Enclosures have front compartments that are designed to be easily accessible. The front compartments and their respective doors typically face walkways. Personnel access the front compartments in order to repair or replace switchgear components located therein.
The door of an enclosure is a potentially vulnerable component because the door by its very nature is designed to open. To prevent the door from being blown off of the enclosure during an arc fault, the door must be latched securely closed and remain closed even when exposed to an interior arc fault.
A door blown loose by an arc fault explosion is dangerous. Doors flying 50 feet or more have been observed.
In the prior art, medium voltage arc-resistant switchgear enclosures use either bolts or latches with concealed latching mechanisms to maintain the doors in closed positions. If bolts are used, loosening all of the bolts to open the door and then tightening all of the bolts to secure the door is tedious and time consuming. If concealed latching mechanisms are used, then it is not possible for personnel to visibly verify that all latching points are fully engaged.